GSDME孔形成与功能调控的结构与机制见解

文献信息

中文摘要

Gasdermin E（GSDME）是gasdermin家族中一个独特的成员，与耳聋、癌症和神经退行性疾病相关，并介导化疗诱导的细胞焦亡；然而，其成孔机制仍知之甚少。在此，我们展示了GSDME孔的冷冻电镜结构，其寡聚化学计量范围为23至29个原体。通过诱变、脂质体渗漏试验和癌症相关突变分析，我们确定了负责膜结合、浅层膜插入以及通过三个不同结构界面进行寡聚化的关键残基。分子动力学模拟揭示了动态脂质招募和特异性：阴离子TMCL2被碱性残基选择性招募以促进浅层膜穿透，而两性离子DPhPC溶剂化极性蛋白区域。在组装的25聚体孔内，特定脂质作为结构稳定剂以增强分子间氢键网络。我们的发现支持GSDME孔组装背后的逐步、时间依赖性机制。这项研究为GSDME功能提供了关键的机制见解，并可能指导针对癌症和神经退行性疾病的靶向治疗开发。

英文摘要

Gasdermin E (GSDME) is a unique member of the gasdermin family linked to deafness, cancer, and neurodegenerative diseases, and mediates chemotherapy-induced pyroptosis; however, its pore-forming mechanism remains poorly understood. Here, we present cryo-EM structures of GSDME pores with oligomeric stoichiometries ranging from 23 to 29 protomers. Using mutagenesis, liposome leakage assays, and analysis of cancer-associated mutations, we identified key residues responsible for membrane binding, shallow membrane insertion, and oligomerization through three distinct structural interfaces. Molecular dynamics simulations reveal dynamic lipid recruitment and specificity: Anionic TMCL2 is selectively recruited by basic residues to facilitate shallow membrane penetration, while zwitterionic DPhPC solvates polar protein regions. Within the assembled 25-mer pore, specific lipids act as structural stabilizers to reinforce the intermolecular hydrogen bond network. Our findings support a stepwise, time-dependent mechanism underlying GSDME pore assembly. This study provides critical mechanistic insights into GSDME function and may guide the development of targeted therapeutics for cancers and neurodegenerative diseases.